Mechanical drive



April 7,1942. w. c. DE ROO 2,278,648.

MECHANICAL DRIVE Filed April 14, 1938 2 Sheets-Sheet l Zmven-tor 2 v 5 :1; 17352722 Gas/fire g h (Ittomegs Aprll 7, 1942. w. .0. DE ROO 2,278,648

MECHANICAL DRIVE I Filed April 14, 1938 2 Sheets-Sheet 2 lllu llllll lllli Zhwentor Patented Apr. 7, 1942 MECHANICAL muvs William C. De R00, Kokomo, Ind., assignor to General Motors Corporation, Detroit, Mich, a

corporation of Delaware Application April 14, 1938, Serial No. 202,027

12 Claims.

This invention relates to mechanical drive means and more specifically to mechanical means for translating straight line movement into rotary movement to index the peripheral position of a rotary member.

which is adapted to have meshed therewith at I certain positions a complementary clutch mem- It is often necessary to index a rotary member at some particular radial position and to do so by means of some straight line movement such as a push button or rack means. The particular adaptation herein shown is utilized for turning the rotary shaft of a yariable condenser in a radio receiving set and to accomplish what has been termed automatic tuning, but this is of course only illustrative of one of the many uses to which this device may be put and therefore the invention should not be limited to its adaptation to a radio receiving set alone. This is desirable for the reason that one'does not have to pay particular attention to just where to set a rotary member but merely push a button and the set is accurately and immediately tuned to that particular station which is received on that radial setting on the condenser.

It is therefore an object of my invention to provide a mechanical index drive for a rotating part.

It is a further object of my invention to provide a mechanical automatic tuning control for radio receiving sets.

With these and other objects in view the embodiments of my invention are more fully described in the following specification and claims and are illustrated in the accompanying drawings, in which:

Figure 1 shows a partial face view of a radio set with my invention applied thereto;

Figure 2 shows an enlarged horizontal section showing the mechanical drive of my invention;

Figure 3 is a sectional view taken on line 3-4 of Figure 2;

t Figure 4 is a vertical section showing a detail of my invention; I

Figure 5 shows a sectional view through the mounting of the cam on the shaft, and;

Figure 6 shows a detail of a modified form of my invention.

Referring now more specifically to the drawings, a cabinet 2 is provided within which is housed a radio receiving set designated generally at d and extending from which there is a tuning shaft 6 upon which is rigidly secured a gear 8 for tuning purposes. Spaced a short distance therefrom and rotatably mounted on the shaft 6 is a further gear 10 for the same purpose. Integral with the gear to is a toothed clutch member 12 ber it which is non-rotatably secured on the shaft 6. This shaft 6 projects outside of the casing 2 and on the end of the shaft 6 there is provided a stationary washer l8 and extending from the outer face of the clutch member It to the washer is a helical spring normally tending to push the clutch halves together and cause engagement.

Carried by the casing 2, spaced from and parallel to the first shaft 6, is a countershaft 22 upon which is mounted an arcuate gear 25 which is adapted to mesh with' the gear 8 so that through a certain angular movement any rotation of the shaft 22 will cause a corresponding rotation of the shaft tthrough gear 8 and consequently the tuning of the radio set. This shaft 22 is journaled in bearings 26 upset from the side walls of the casing and also carries a pulley wheel 28 which is adapted to rotate a dial 30 supported on a shaft 32 through a second pulley 3t and a belt 36. The dial 39 has certain configurations on its face and is adapted to be viewed through a rectangular opening 38 in the forward wall of the casing 2.

There is also provided on the shaft 22 a plurality of spaced annular discs til which are mounted in pairs. These discs 50 are mounted on sleeves 62 around the shaft 22 and these sleeves 62 are pressed on the shaft 22 and rotatetherewith.

Between the two discs forming a pair there is mounted a cam member it and riding against the two outside faces of the disc ii] are a pair of spring washers which are engaged in a slight notch 58 in the outer surface of the sleeve 52. This construction is of course best shown in Figure 5 and forms a unitary construction for each one of the pairs of discs 40, the two springs 66 pressing the circular discs toward each other and clamping between them the cam member 44.

It will be noted that this cam member 44 is also journaled on the sleeve 42 but it may rotate with respect thereto and is maintained rotatable with the shaft 22 by the pressure of the two discs 40 so that under normal conditions when a force is tuned'in automatically or morebroadly, six difslidable members 50, each having a slot 52 therein through which this bar 48 passes thereby providing a slot so that the member 50 may slide "back and forth upon the transverse member 48. The forward end of the member 50 is provided with a push button member 54 and the rear portion is cut to form a U-shaped slot 56.

There is also secured between the casing and the member 50 a tension spring 58 to bias the slidable member toward its outermost position with the button 54 projecting from the forward face of the casing, said button being journaled in an opening 80 therein. The jaws adjacent the U-shaped slot 56 are adapted to be reciprocated between the pairs of discs 40 and to surround the shaft 22 when in their innermost position and cam the surface of the frictionally mounted cam 44 engaged to turn the shaft.

With special reference now to Figures 3 and 4, the former figure shows the cam in one of its extreme positions and it will be noted that the forward nose of the member 50 will contact with the cam 44 and tend to position it in the direction of the arrow to its horizontal dotted line position which is clearly shown in the relationship illustrated in Figure 4 and is the position assumed when the push button is forced to its extremity. This is the position at which the shaft and the condensers thereon are in the proper position for the reception of a desired station, the distance from either extremity to this position being such as to cover the total range of the condensers in the radio set.

There is also provided on the side surface of each one of the members a raised portion 52 and slidably 'mounted in a parallel position to the bar 48 is a movable bar 64 having a plurality of pins 66 extending downwardly adjacent the raised portion 82 so that as the member 50 is pressed inwardly this raised surface will act as a cam against the pin 66 and cause the bar 64 to move to the left. This will cause movement of an arm 68, the end of which engages an opening" in the bar 64, said bar 88 being pivoted to a rod 12 which is journaled in a pair of ears 14 struck out from the side of the casing 2. To the opposite end of the rod 12 there is secured a further lever 18, the end of which engages an annularnotch 18 in the movable clutch member l4 to cause the same to be disengag'ed.

Meshing with the gear Hi there is provided a worm 80 which is mounted on a shaft 82 journaled in a member 84 on the base of the casing 2, said shaft extending forwardly and projecting through an opening 86 in the forward face of the casing 2 and having provided thereon a manually engagea-ble knob 88 for manually turning the tuning shaft either for tuning in a station or for the initial setting of the cam means between the discs.

There is also provided a further knob 90 and its associated control Shaft 92 for the volume control of the set, said shaft extending back into the conventional receiver. It is therefore obvious that when all of the control knobs 54 are in their outermost position that the clutch l2, I4 is in engagement due to the spring bias of the spring 20 and'if the knob 88 is rotated it will drive through gear I0 and clutch l2, I4 the shaft 6 to tune in the usual manner. However, if one of the knobs 54 is pressed inwardly the cam'surface 62 will cause its adjacent pin I 66 to shift, thus disengaging the clutch l2, l4

and during the automatic tuning the set cannot be manually tuned. However, when it is desired to set one of the cams 44 in a position which ,will give reception of a particular station, one

of the knobs 54 is fully depressed and held in that position and in this instance as clearly shown in Figure 4 the pin 66 overrides the forward end of the camming surface 62 and allows the clutch l2, l4 to again engage and while the cam 44 is held in its locked position the condenser shaft may be tuned manually through the knob 88 until the desired station is in correct'tune causing a relative movement between the cam and shaft to initially set the cam. The button 54 is then released and every time thereafter this button is depressed will return the shaft through the gear 24 and the tuning shaft 6 to that same radial position.

Of course it will be necessary to set each one of these cams 44 initially to a desired station but after that any depression of the knob 54 in that position will always return the condenser shaft to that given desired index.

Figure 6 shows a slight variation in which the cross bar 64' instead of moving a lever 68 operates a switch 90 supported on the casing 2, said switch being connected to a remote source of current 92 and also to a solenoid coil 94 supported adjacent the outer end of the shaft 6. The solenoid armature 96 in this instance projects parallel to the shaft 6 and has adjacent its end a small disc washer 98 which rides in the groove I00 of the clutch member I4 so that when the solenoidis energized it will pull the two halves of the clutch apart and perform the same function as the lever It did in the former instance.

I claim:

1. In a device of the class described, a shaft, a plurality of pear-shaped cams frictionally mounted in spaced relation on the shaft, a radially movable lever adjacent each cam and being slotted to provide a complementary groove to the cam outline so that as the lever is moved in, the cam will be turned until it nests within the groove and then always comes to the same position regardless of its initial position to index the angular position of the shaft.

2. In a device of the class described, a shaft, means for manually turning the shaft, a clutch means for disconnecting the manual drive, a second shaft, gearing means interconnecting the two shafts, cam means on the second shaft, long'itudinally movable means adjacent the cam means to turn the latter and further means actuated by the longitudinal movement of the movable means .to disengage the clutch to preventmanual movement.

3. In a device of the class described, a shaft, means for manually turning the shaft, a clutch means for disconnecting the manual drive, a second shaft, gearing means interconnecting the two shafts, cam means on the second shaft, lonvent manual movement. said disengagement not effective at the two extremities of travel of the longitudinally movable means so that the manual means may be actuated at. these positions.

4. In a mechanical drive, a shaft which it is desired to index at different angular positions, a clutch connected to the shaft, manually rotat- ,able means connected to the clutch, a second cam engagement at both extremities of lever travel whereby the first shaft may be manually turned to index the cams when the levers are in their actuated position and hold the cams.

5. In a mechanical drive, a shaft, a second shaft parallel to the first and spaced therefrom, interconnecting driving means, a. plurality of pairs of means spring biased toward each other on the second shaft, cam means between each pair and normally turning with the means and second shaft but capable of being moved with respect thereto and driving means for engaging the cam means to cause the shafts to be rotated. 6. In a mechanical drive, a shaft which it is desired to index to a predetermined point, a sec- ,ond shaft, interconnepting means for causing the one to rotate the other, a pair of spaced discs mounted on the second shaft, spring means for biasing the two toward each other, cam means clamped between the discs, means having a complementary outline to that of the cam movable in a radial direction to engage the cam and turn it to a given position whereby the second shaft will be turned a given amount and index the first shaft.

'7. In a device of the class described, a shaft which it is desired to index to a plurality of different angular positions, a control shaft, gearing interconnecting the two shafts, manual means for driving the first shaft connected to the shaft beydnd the gearing, clutch means interposed between the manual means and the shaft inthe driving connection, a plurality of means for driving the control shaft to different angular positions automatically and simultaneously operate the clutch whereby the two shafts are always connected together for rotationbut the manual means may be disconnected from the first shaft.

. 8. In a device of the class described, a, pair of rotatable shafts. gearing interconnecting said shafts, a plurality of axially spaced cam means frictionally mounted on one of the shafts, cooperatingoperating means for each of said cams, manual operating means, clutch means connectin said manual means to the other shaft and means interconnecting said clutch means and said operating'means to maintain the clutch in disengaged position except when the operating means is in either extremity of travel.

9. In a device of the class described, a rotatable shaft that it is desired to index to a plusecond shaft, gearing interconnecting the two shafts whereby they rotate simultaneously, a plurality of elongated cams axially spaced and frictionally mounted on the second shaft to normally rotate therewith but capable of motion with respect thereto. a pluralityv of reciprocable arms cooperating with said cams having a complementary surface with respect to the cam surface so that when forced together a certain definite position of' the cam will always be assumed, said arms being supported for movement radially of the shaft, a raised cam surface on the side of each arm, an arm movable in a plane parallel to the axis of the second shaft, spaced pins carried by the arm to contact the raised cam surfaces of the different arms and means connecting the last named arm tocthe clutch whereby when any arm is depressed to turn the first shaft by cam means the clutch will be actuated for declutching.

10. A mechanical station selector type tuner for a radio receiver comprising, in combination, an actuator movable generally reetillnearlyv and having a recess in its forward end bordered by spaced forwardly projecting portions on opposite sides thereof, an elongated generally fiat peripheral cam positioned in front of said actuator and lying in the plane of said projecting portions of said actuator, means for supporting said cam for oscillation in said plane about an axis longitudinally eccentric to the center of said elongated 'cam and transverse to the .path of moveend of said cam facing generally away from said actuator and never directly toward the same, means for connecting said cam in driving relation with a tuning element of a radio receiver, and means for moving said actuator toward said cam to cause said projecting portions of said actuator to contact alternative adjacent edges of said cam and push the same around to a predetermined position in which the longitudinal axis of said elongated cam projects away from said actuator in substantial alinement therewith.

11. A mechanical station selector type radio receiver tuner comprising, in combination, an elongated peripheral cam, means supporting said cam for rotation about a transverse axis passing through a butt end portion of said cam with the opposite elongated end portion thereof extending radially from said axis and for connecting said cam in driving relation with the tuning eleposite sides of said axis and contactible with alternative side edges of said cam for rotating the same to a redetermined tuning position, said recess being dimensioned to embrace said butt end of said cam when the latter is in said predetermined position, the bottom of said recess and said butt end of said cam being provided with complemental surfaces for locating said cam precisely in said predetermined position.

, 12. In a mechanism for positioninga control of a radio device, a combination including; a rotatable shaft; 9. positionable member adjustably mounted upon said shaft; positioning means for turning said member in either direction to a position at which said means presses against said member on both sides of said shaft in substantially parallel directions; said means having a first shoulder adapted to engage and turn said member in one direction only and a second shoulder WILLIAM C. DE ROO- 

